Ticket #5240: 0001-Rework-fix-for-5240-to-avoid-spamming-the-output-wit.patch

aclocal.m4

@@ -459 +459 @@
     fi
 
     # Reduce memory usage when linking. See trac #5240.
-    if test -n "$LdHashSize31"
-    then
-        $3="$$3 -Wl,$LdHashSize31"
-        $4="$$4     $LdHashSize31"
+    if test "$LdHashSize31" = "YES"; then
+        $4="$$4     --hash-size=31"
     fi
-    if test -n "$LdReduceMemoryOverheads"
-    then
-        $3="$$3 -Wl,$LdReduceMemoryOverheads"
-        $4="$$4     $LdReduceMemoryOverheads"
+    if test "$LdReduceMemoryOverheads" = "YES"; then
+        $4="$$4     --reduce-memory-overheads"
     fi
 
     rm -f conftest.c conftest.o
@@ -880 +876 @@
 ])# FP_PROG_LD_X
 
 
-# FP_PROG_LD_HashSize31
-# ------------
-# Sets the output variable LdHashSize31 to --hash-size=31 if ld supports
-# this flag. Otherwise the variable's value is empty.
-AC_DEFUN([FP_PROG_LD_HashSize31],
+# FP_PROG_LD_HASHSIZE31
+# ---------------------
+
+# Sets the output variable LdHashSize31 to YES if ld supports
+# this flag. Otherwise the variable's value is NO.
+AC_DEFUN([FP_PROG_LD_HASHSIZE31],
 [
-FP_PROG_LD_FLAG([--hash-size=31],[LdHashSize31])
-])# FP_PROG_LD_HashSize31
+AC_CACHE_CHECK([whether ld understands --hash-size=31], [fp_cv_ld_hashsize31],
+[echo 'foo() {}' > conftest.c
+${CC-cc} -c conftest.c
+if ${LdCmd} --hash-size=31 -o conftest2.o conftest.o > /dev/null 2>&1; then
+   fp_cv_ld_hashsize31=yes
+else
+   fp_cv_ld_hashsize31=no
+fi
+rm -rf conftest*])
+if test "$fp_cv_ld_hashsize31" = "yes"; then
+  LdHashSize31=YES
+else
+  LdHashSize31=NO
+fi
+AC_SUBST([LdHashSize31])
+])# FP_PROG_LD_HASHSIZE31
 
 
-# FP_PROG_LD_ReduceMemoryOverheads
-# ------------
-# Sets the output variable LdReduceMemoryOverheads to
-# --reduce-memory-overheads if ld supports this flag.
-# Otherwise the variable's value is empty.
-AC_DEFUN([FP_PROG_LD_ReduceMemoryOverheads],
+# FP_PROG_LD_REDUCEMEMORYOVERHEADS
+# --------------------------------
+
+# Sets the output variable LdReduceMemoryOverheads to YES if ld supports
+# this flag. Otherwise the variable's value is NO.
+AC_DEFUN([FP_PROG_LD_REDUCEMEMORYOVERHEADS],
 [
-FP_PROG_LD_FLAG([--reduce-memory-overheads],[LdReduceMemoryOverheads])
-])# FP_PROG_LD_ReduceMemoryOverheads
+AC_CACHE_CHECK([whether ld understands --reduce-memory-overheads], [fp_cv_ld_reduce_memory_overheads],
+[echo 'foo() {}' > conftest.c
+${CC-cc} -c conftest.c
+if ${LdCmd} --reduce-memory-overheads -o conftest2.o conftest.o > /dev/null 2>&1; then
+   fp_cv_ld_reduce_memory_overheads=yes
+else
+   fp_cv_ld_reduce_memory_overheads=no
+fi
+rm -rf conftest*])
+if test "$fp_cv_ld_reduce_memory_overheads" = "yes"; then
+  LdReduceMemoryOverheads=YES
+else
+  LdReduceMemoryOverheads=NO
+fi
+AC_SUBST([LdReduceMemoryOverheads])
+])# FP_PROG_LD_REDUCEMEMORYOVERHEADS
 
 
 # FP_PROG_LD_BUILD_ID

compiler/ghc.mk

@@ -105 +105 @@
         @echo 'cRAWCPP_FLAGS         = "$(RAWCPP_FLAGS)"'                   >> $@
         @echo 'cLdHasNoCompactUnwind :: String'                             >> $@
         @echo 'cLdHasNoCompactUnwind = "$(LdHasNoCompactUnwind)"'           >> $@
+        @echo 'cLdHashSize31         :: String'                             >> $@
+        @echo 'cLdHashSize31         = "$(LdHashSize31)"'                   >> $@
+        @echo 'cLdReduceMemoryOverheads :: String'                          >> $@
+        @echo 'cLdReduceMemoryOverheads = "$(LdReduceMemoryOverheads)"'     >> $@
         @echo 'cLdIsGNULd            :: String'                             >> $@
         @echo 'cLdIsGNULd            = "$(LdIsGNULd)"'                      >> $@
         @echo 'cLdHasBuildId         :: String'                             >> $@

compiler/main/DriverPipeline.hs

@@ -1775 +1775 @@
                           then ["-Wl,-no_compact_unwind"]
                           else [])
 
+                      -- Reduce linker memory usage dramatically by setting the
+                      -- hash size to 31 and enabling the "reduce memory
+                      -- overheads" option (if possible).  See #5240.
+                      ++ (if cLdHashSize31 == "YES"
+                          then ["-Wl,--hash-size=31"]
+                          else [])
+
+                      ++ (if cLdReduceMemoryOverheads == "YES"
+                          then ["-Wl,--reduce-memory-overheads"]
+                          else [])
+
                       -- '-Wl,-read_only_relocs,suppress'
                       -- ld gives loads of warnings like:
                       --     ld: warning: text reloc in _base_GHCziArr_unsafeArray_info to _base_GHCziArr_unsafeArray_closure

configure.ac

@@ -533 +533 @@
 dnl
 FP_CC_LLVM_BACKEND
 
-FP_PROG_LD_HashSize31
-FP_PROG_LD_ReduceMemoryOverheads
+FP_PROG_LD_HASHSIZE31
+FP_PROG_LD_REDUCEMEMORYOVERHEADS
 
 FPTOOLS_SET_C_LD_FLAGS([target],[CFLAGS],[LDFLAGS],[IGNORE_LINKER_LD_FLAGS],[CPPFLAGS])
 FPTOOLS_SET_C_LD_FLAGS([build],[CONF_CC_OPTS_STAGE0],[CONF_GCC_LINKER_OPTS_STAGE0],[CONF_LD_LINKER_OPTS_STAGE0],[CONF_CPP_OPTS_STAGE0])

mk/config.mk.in

@@ -735 +735 @@
 # and compiler/main/DriverPipeline.hs.
 LdHasNoCompactUnwind    = @LdHasNoCompactUnwind@
 
+# Set to YES if ld has the --hash-size flag.  See #5240.
+LdHashSize31            = @LdHashSize31@
+
+# Set to YES if ld has the --reduce-memory-overheads flag.  See #5240.
+LdReduceMemoryOverheads = @LdReduceMemoryOverheads@
+
 # On MSYS, building with SplitObjs=YES fails with 
 #   ar: Bad file number
 # see #3201.  We need to specify a smaller max command-line size